Core.



PATENTED MAY 15@ 15166 M. H. FLETCHER.

CORE. APPLIOATIO FILED Am. 1o. 19%,

it-nesses.

- V einrzr.

UNITED STATES rA'rnu'r OFFICE.

CORE.

i Specification of Letters Patent.

Application filed April 10.

To rail, whrmt it may concern.-

Be a t known th at LMonnEcAr I l. FLE'HliIFiR',

a citizen of the United States, residing at Cincinnati, in the county of Hamilton and State of Ohio, have invented new and use-fut improvements in Cores, ol" whichthe foiiowmg 18 e specification.

My invention relates tocoree employed in caetm hoiiow metal articles, and more perro; ticuiar y hollow'cylindricel pipe? wherein upon ametal core-barrel issupe'rnnposed a concentric layer of combustible material and then a. coresurface ofsand, loam,or the like.

At present in making cores for casting iron- 1'5 pipes such as are used for gas, water, &c., the

ordinary practice is to wrap ciosciy upon a metal core-bar which has been previously perforated for venting hay, straw, or like meterialin the form of rope, so wrapped around 20 the barrel as to make as neariy es pcsieihie a solid combustible layer. "Upon this layer ofv hey rope is placed a coating of clay in plastic ,etete. This coating is then thorcughlydried. After drving there is superim osed a final concentric layer of loam whic when dried rind suitabl blackened exteriorly forms the casting-SUI ace of the core. Thc'hcat of the molten metal surrounding this core causes the layer of hay rope to be consumed, leaving 0 a space between the core-barre! and the non combustible layer sul'licicnt to enable the core-bar to he withdrawn. Certain difficulties and disadvantages enccu n'tere'd with this method are hrielly as follmvsrFirst, even wi t-h' careful winding there are at times space 4o culty is increased because of luck of s rn-1- i metry and uml'ornnty of size of the rope. 5

and rope into which the plastic clay is pressed as the clay layer is put upon the her, tending to prevent withdrawal of the her. This diffi- Then under the intense heat of the 'inolten iron the clay burns tight to the. core-her,

the pipe; third, two zirving operations are the hay rope itself required, causing double costof labor in handling and more than double the amount of fuel because of greater quantity of material to be dried as well as two dryings': fourth,

combustible lover is 1 hick and because i the chinks left between the strands of he I the inner surface oi v is expensive; lil'th, the 1 Patented May 15, 1906. 1905. Serial m1 254,740.

lack of its uniformity the succeeding ieyers are necessarily thick to secure an even castingof large; unntities of material with conscqnent IKlt ed expense. All these difficulties end disadvantages are overcome in; my improved core, with which a pipe with a cylindrical opening of six inches in diameter may he carat on aiiveiand one-helf'inch core-Bar rel, whereas formerl a. core-barrel four and one-half inches to ve inches in diameter would have been used. In this size therefore I would build up not over one-half the thick ness of combined combustible and surfacing materiel. Still the ber may always be drawn withease. I t 7 To this end my invention consists of'a' core huiltupon a metal core-barrel suitably vented, in which instead of the'hey rope I substi- I hereto, illuetrating the structural features' of the core designed for use in casting cylindrical pipes,

ed metal core-barrel partially wound spirally form and a part of the so woundportion partially coated with the finish ngdayer 01' learn. Fig. 2, a transverse cross-section of a completed core;

surface, necessitating the use and handling tute a foundation-layer d paper or other Figure I exhibits an exterior View of event with a strip of combustible material in sheet Fig. 3; a perspective of one kind of combustible metcrial, showing'thc compcnent sections'parted at one end.-

Referring to the drawings-i, C designatee a metal core-barre nhnmiently rented by suitahledrill or other holes; e to 't the escape of gases formal hr heating the earth forming a herd hrickv mass which adheres to 1 layer and the burning oi the layer of combustililomutvriel, &c.

:igiiinst which when coated withthe blackin The loam tsc the molten metal is poured.

composing thi layer is designated by the letu-r r. 'llu-r ('umllllr-lllllll. layer is in sheet i'urni, may he e-mnpused of layers, end'may I CO have an exterior layer impervious to moistore or whose sustaining power is not impaired by the action of water, which is to be next the loam layer. a sustaining layer when usin the cheap apers, as carpet-papers, which use their .00 1csion when long subjected to moisture and which \vouldcease to form a close-fitting layer concentric with the core-bar unless held in place. These layers I have designated as p, a sustaining layer, and an inner readily-mmbustible layer, of which there may be one or more, according to thickness desired. More than one such combustible sheet layer may be applied, if needed.

The-combustible strip may be wound on by hand or any other convenient way and may be held in place by adhesive material or preferably by tying with thin 'cord or-soft wire. All superfluous or overhanging portions may be trimmed away at either end of the bar, or, if applied in a strip, by having the strip previous y the starting end, and by cutting it at a like angle at the finishing end all waste may be avoided. The loam or finishing layer is turned upon the bar in the usual way after it is wrapped with the combustible layer.

, plete he loam layer is then dried and usually blackened on its surface when the core is ready to place int-he mold.

The combustion of the layer P while cornbecause of the intense heat of the molten metal surroundi'n it is sufliciently slow to enable the loam or iinishing layer to retain its proper form until the metal sets. The combustible layer if not sufficiently porous may be perforated at v for venting and in connection with the vents 1; permit thefree escape of gasesengendered in casting, as w'ell as permit sufficient admission of air to properly sustain combustion.

A properapplieation of the invention will secure more smooth and uniform castings at a smaller cost and greatly decrease the percentage of failures or castings soimperfeet as to necessitate rejection.

I. claim as my invention and desire to "secure by Letters Patent of the United States I. An improved core for casting hollow objects of metal, consisting of a metal core-barrel having applied thereto a concentric rombustible compound la er, whose outer sec tion is waterproof, in s wet form wound on ll) cut at a suitable bevel at l i. l

a s iral strip and secured in on of the core-barrel, and upon this a concentric layer of loam to form the casting-sur- I prefer the use of such face.

2. An iln roved core for casting hollow pipes'and tlie like consistin of the metal core-barrel wra ped in aspire direction with it strip of com ustible material applied directly to said core-barrel, said strip having flat sides and a substantially uniform diameter from edge to edge, and a non-co1nbustible outer layer. r

3. An improved core for casting pipes consisting of the metal core-barrel wrapped in a spiral direction with a'relatively wide and thin strip of combustible material Whose inner surface is applied direct to the surface of the core and whose outer surface is rendered im ervious to moisture, and a non-combustib eouter layer.

4. An improved core for casting pipes, consisting of a metal-core-barrel wrapped in a spiral direction with a relatively wide and thin strip of combustible material, perforated for venting, whose inner'surface is ap lied directly to the surface of the core an whose outer surface is rendered impervious to moisture, and a non-combustible outer layer.

5. A core for casting hollow pipes and the like consisting of the metal core barrel wrapped with a combustible layer in'sheet form applied directly to'said core-barrel, and one or more non-combustible outer layers.

6. A core for casting metal pipes andthe like, consisting of a properly-vented metal core-barrel wrapped with a combustible layer in sheet form applied directl to said corebarrel spirally, said combustible layer secured to said core-barrel, and one or more non-combustible outer layers.

7. A core for casting hollow ipes and the like consisting of the metal? corebarrel wrap ed with a suitably-perforated combustible ayer in sheet form, applied directly to said core-barrel, and one or more non-combustible outer layers. l i

In testimony whereof I have hereunto set my hand in presence of two subscribing wit- 1183383.

MoRDEcAI n. FLETCHER. Witnesses: i

' Jossrn ltGmcnicu, n/is. HERBERT Jonas,

position at each 

